Comparative study of phytochemical screening, antioxidant and antimicrobial capacities of fresh and dry leaves crude plant extracts of Datura metel L

Abstract

The aim of this work is to investigate and compare the phytochemical screening, antioxidant and antimicrobial activities of different crude extracts from dry and fresh leaves of Datura metel L. Different organic solvents including methanol, chloroform, hexane, ethyl acetate and butanol were used to prepare the crude extracts from the fresh and dry leaves. Antioxidant and antimicrobial activities of different crude extracts from dry and fresh leaves of D. metel were determined by DPPH method and agar disc diffusion method with minor modification. In vitro phytochemical screening for all crude extracts from both dry and fresh leaves was tested and shown positive result for alkaloid, flavonoid, saponin and tannin compounds. However, all the crude extracts did not show positive results for steroids and triterpenoid compounds. The antioxidant activity results of both fresh and dry crude extracts showed that when gradually increasing the samples concentration there was an increase in the absorbance. Therefore the antioxidant activity of dry crude extracts as equivalent to DPPH (2, 2-diphenyl-1-picrylhydrazyl) was in the order of butanol>chloroform>ethyl acetate extract>methanol>hexane extract. However, the order of antioxidant activity for fresh organic crude extracts to DPPH was in order of methanol>hexane>chloroform>ethyl acetate extract>butanol. The methanol crude extract and its derived fractions from dry and fresh leaves showed small and moderate antibacterial potential with one gram positive (Staphylococcus aureus) and three gram negative(Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) bacteria in the range of 0–17%. In conclusion, all organic crude extracts from both fresh and dry leaves could be used as potential sources of new antioxidant and antimicrobial agents.